1. Field of the Invention
The present invention relates to an authentication system for a user terminal to receive a user authentication from an authentication server and to request a service offered by an application server on the basis of the authentication received, and in particular, to an authentication system in which upon a successful user authentication, the authentication server allocates a source address to the user terminal and the user requests a service offered by the application server using the allocated source address, and an apparatus and a program therefor.
2. Description of the Related Art
When a user desires to obtain a service from a server through a network such as the internet, it is a general practice that a session be established between the terminal of the user (the user terminal) and the server and that a service request is sent to the server through the session. For the sake of charging for the service offered by the server, the latter requires a user authentication before the service is offered, and upon successful authentication, it offers the service through the established session. Thus, the user authentication takes place each time a service request to the server is made, and the service is offered through the established session. If the service offered covers a plurality of packets, the service is offered through the same session.
In view of an increased throughput experienced by each application server if a user authentication is performed in response to each service request, there is proposed a method in which a user authentication is performed by an authentication server, which upon successful authentication, allocates an IP address to the user, who then requests the server for a service to be offered using the IP address as a source address.
In the prior art network authentication system, such an address based authentication method as indicated below is disclosed in patent literature1, for example. Specifically, when a user utilizes a connection service, a network access authentication server refers to a personal information database in which a correspondence between a customer information and a user ID (information which uniquely identifies a user) is pre-stored in order to authenticate the user, and upon successful authentication, allocates an IP (Internet Protocol) address to the user's terminal together with a connection grant, transmits the allocated IP address to the user terminal while concurrently storing the relationship between the IP address and the user ID in a storage, and when utilizing a commercial transaction service, the user terminal proposes a purchase of goods to a sales service provider apparatus on the internet using the IP address transmitted from the network access authentication server, the sales service provider address obtains the source IP address of a goods purchase proposal packet and sends this IP to the network access authentication server for inquiry and acquires the user ID on the basis of the IP address and then acquires the customer information which corresponds to the acquired user ID for purpose of authenticating the customer.    Patent literature 1: JP Application Kokai Publication No. 2002-207929